URLRewriter实现
可以参考下面的文章
代码
.net framework
新建asp.net framework的web项目，新建AntiTheftChainHandler
using System.Web;namespace AntiTheftChainStu01.Handler
{public class AntiTheftChainHandler : IHttpHandler{public bool IsReusable => true;/// <summary>/// jpg文件防盗链/// </summary>/// <param name="context"></param>public void ProcessRequest(HttpContext context){string FileName = context.Server.MapPath(context.Request.FilePath);string notFoundFile = context.Server.MapPath("/404.jpg");if (context.Request.UrlReferrer ==null|| context.Request.UrlReferrer.Host == null){context.Response.ContentType = "image/JPEG";context.Response.WriteFile(notFoundFile);}else{//此处的可填你网站的域名，因为我这里采用的是本机演示，故使用localhostif (context.Request.UrlReferrer.Host.IndexOf("localhost") != -1){context.Response.ContentType = "image/JPEG";context.Response.WriteFile(FileName);}else{context.Response.ContentType = "image/JPEG";context.Response.WriteFile(notFoundFile);}}}}
}
修改web.config
<system.webServer><!-- 确保所有请求都经过ASP.NET的管道处理 --><modules runAllManagedModulesForAllRequests="true" /><handlers><add name="jpgHandler" path="*.jpg" verb="*" type="AntiTheftChainStu01.Handler.AntiTheftChainHandler,AntiTheftChainStu01" /></handlers><!--设置默认起始页面--><defaultDocument><files><clear /><add value="Index.aspx" /></files></defaultDocument>
</system.webServer>
新建测试的html
<!DOCTYPE html>
<html lang="zh">
<head><meta charset="UTF-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><title>Document</title>
</head>
<body><img src="http://localhost:63099/image/imgs/002.jpg" alt="">
</body>
</html>
最后效果如下
微信公众号图片也是实现的类似的效果
.net core
新建中间件RefuseStealingMiddleWare
namespace AntiTheftChainStu02
{public class RefuseStealingMiddleWare{private readonly RequestDelegate _next;public RefuseStealingMiddleWare(RequestDelegate next){_next = next;}public async Task Invoke(HttpContext context){string url = context.Request.Path.Value;if (!url.Contains(".jpg")){await _next(context);//走正常流程return;}string urlReferrer = context.Request.Headers["Referer"];if (string.IsNullOrWhiteSpace(urlReferrer))//直接访问{await this.SetForbiddenImage(context);//返回404图片}else if (!urlReferrer.Contains("localhost"))//非当前域名{await this.SetForbiddenImage(context);//返回404图片}else{await _next(context);//走正常流程}}/// <summary>/// 设置拒绝图片/// </summary>/// <param name="context"></param>/// <returns></returns>private async Task SetForbiddenImage(HttpContext context){string defaultImagePath = "wwwroot/404.jpg";string path = Path.Combine(Directory.GetCurrentDirectory(), defaultImagePath);FileStream fs = File.OpenRead(path);byte[] bytes = new byte[fs.Length];await fs.ReadAsync(bytes, 0, bytes.Length);await context.Response.Body.WriteAsync(bytes, 0, bytes.Length);}}
}修改Program.cs
namespace AntiTheftChainStu02
{public class Program{public static void Main(string[] args){var builder = WebApplication.CreateBuilder(args);var app = builder.Build();app.UseMiddleware<RefuseStealingMiddleWare>();app.UseDefaultFiles();app.UseStaticFiles();app.Run();}}
}新建index.html
<!DOCTYPE html>
<html lang="zh">
<head><meta charset="UTF-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><title>Document</title>
</head>
<body><img src="https://localhost:7229/image/imgs/001.jpg" alt="">
</body>
</html>
参考
https://cloud.tencent.com/developer/article/1459550
https://www.cnblogs.com/mbskys/articles/633043.html
https://blog.csdn.net/net_programmer1/article/details/136627093
https://blog.csdn.net/weixin_42084199/article/details/110874803
